Abstract: A turbomachine includes an annular casing and a fan disposed inside the annular casing and mounted for rotation about an axial centerline. The fan includes fan blades that extend radially outwardly toward the annular casing. The fan has an average chord fan width according to a first performance factor. The fan has a quantity of fan blades according to a second performance factor.

Abstract: A cascade thrust reverser assembly for a gas turbine engine includes a nacelle assembly defining a bypass passage. The cascade thrust reverser assembly includes a cascade assembly configured to be at least partially enclosed by the nacelle assembly, the cascade assembly comprising one or more cascade members, the one or more cascade members movable between a stowed configuration wherein the one or more cascade members define a first radial extent and a deployed configuration wherein the one or more cascade members define a second radial extent, wherein the one or more cascade members form a cascade segment in the deployed configuration, and wherein the second radial extent is greater than the first radial extent.

Abstract: A turbofan engine is provided. The turbofan engine includes a fan comprising a plurality of fan blades; and a nacelle that circumferentially surrounds the fan, the nacelle comprising an annular wall having an exterior surface and an interior surface, the exterior surface comprising a first exterior portion, and the interior surface comprising a first interior portion, wherein a first exterior portion is formed of a first structure defining an exterior surface porosity, and wherein a first interior portion is formed of a second structure defining an interior surface porosity.

Abstract: A turbofan engine is provided. The turbofan engine includes a fan comprising a plurality of fan blades; and a nacelle that circumferentially surrounds the fan, the nacelle comprising an annular wall having an exterior surface and an interior surface, the exterior surface comprising a first exterior portion, and the interior surface comprising a first interior portion, wherein a first exterior portion is formed of a first structure defining an exterior surface porosity, and wherein a first interior portion is formed of a second structure defining an interior surface porosity.

Abstract: A cascade thrust reverser assembly for a gas turbine engine includes a nacelle assembly defining a bypass passage. The cascade thrust reverser assembly includes a cascade assembly configured to be at least partially enclosed by the nacelle assembly, the cascade assembly comprising one or more cascade members, the one or more cascade members movable between a stowed configuration wherein the one or more cascade members define a first radial extent and a deployed configuration wherein the one or more cascade members define a second radial extent, wherein the one or more cascade members form a cascade segment in the deployed configuration, and wherein the second radial extent is greater than the first radial extent.

Abstract: A turbomachine includes an annular casing and a fan disposed inside the annular casing and mounted for rotation about an axial centerline. The fan includes fan blades that extend radially outwardly toward the annular casing. The fan has an average chord fan width according to a first performance factor. The fan has a quantity of fan blades according to a second performance factor.

Abstract: An aircraft including a fuselage and an aft engine is provided. The fuselage extends from a forward end of the aircraft towards an aft end of the aircraft. The aft engine is mounted to the fuselage proximate the aft end of the aircraft and includes a fan and a nacelle. The fan is rotatable about a central axis of the aft engine and includes a plurality of fan blades. The nacelle of the aft engine surrounds the plurality of fan blades and defines a bottom portion having a forward end. Additionally, the nacelle defines a curved surface at the forward end of the bottom portion, the curved surface including a reference point where the curved surface defines the smallest radius of curvature. The nacelle further defines a normal reference line extending normal from the reference point. The normal reference line defines an angle with the central axis of the aft engine greater than zero to, e.g., allow for a maximum amount of airflow into the aft engine.

Abstract: An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The fuselage defines a profile proximate the boundary layer ingestion fan that is optimized for ingesting a maximum amount of boundary layer air and improving propulsive efficiency of the aircraft. More specifically, the fuselage defines a cross sectional profile upstream of the boundary layer ingestion fan that has more cross sectional area in a top half relative to a bottom half as defined relative to a centerline of the boundary layer ingestion fan.

Abstract: A method for operating an electric fan of an aircraft propulsion system includes driving a plurality of fan blades of the electric fan with an electric machine to generate thrust for the aircraft; and driving the electric machine with the plurality of fan blades of the electric fan to generate electrical power subsequent to driving the plurality of fan blades of the electric fan with the electric machine to generate thrust for the aircraft.

Abstract: An aircraft includes a boundary layer ingestion fan defining a centerline and including a plurality of fan blades rotatable about the centerline. The aircraft also includes a fuselage extending between a forward end and an aft end along a longitudinal direction, the boundary layer ingestion fan positioned within the fuselage at the aft end of the fuselage, the fuselage defining an inlet upstream of the boundary layer ingestion fan extending at least about 180 degrees around the centerline of the boundary layer ingestion fan, the fuselage further defining an exhaust downstream of the boundary layer ingestion fan.

Abstract: A method for operating an electric fan of an aircraft propulsion system includes driving a plurality of fan blades of the electric fan with an electric machine to generate thrust for the aircraft; and driving the electric machine with the plurality of fan blades of the electric fan to generate electrical power subsequent to driving the plurality of fan blades of the electric fan with the electric machine to generate thrust for the aircraft.

Abstract: An aircraft is provided including a propulsor having a plurality of fan blades. The aircraft additionally includes a fuselage, with the propulsor attached to the fuselage at an aft end of the fuselage. A stabilizer extends away from the fuselage proximate the aft end, the stabilizer including a portion positioned upstream of the plurality of fan blades. The aircraft additionally includes an airflow duct extending between an inlet and an outlet. The inlet is positioned to receive an airflow from a location outside the fuselage of the aircraft. The outlet is positioned to exhaust the airflow to at least partially offset a wake upstream of the plurality of fan blades, the wake generated by the stabilizer during operation of the aircraft.

Abstract: An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The fuselage defines a profile proximate the boundary layer ingestion fan that is optimized for ingesting a maximum amount of boundary layer air and improving propulsive efficiency of the aircraft. More specifically, the fuselage defines a cross sectional profile upstream of the boundary layer ingestion fan that has more cross sectional area in a top half relative to a bottom half as defined relative to a centerline of the boundary layer ingestion fan.

Abstract: An aircraft including a fuselage and an aft engine is provided. The fuselage extends from a forward end of the aircraft towards an aft end of the aircraft. The aft engine is mounted to the fuselage proximate the aft end of the aircraft and includes a fan and a nacelle. The fan is rotatable about a central axis of the aft engine and includes a plurality of fan blades. The nacelle of the aft engine surrounds the plurality of fan blades and defines a bottom portion having a forward end. Additionally, the nacelle defines a curved surface at the forward end of the bottom portion, the curved surface including a reference point where the curved surface defines the smallest radius of curvature. The nacelle further defines a normal reference line extending normal from the reference point. The normal reference line defines an angle with the central axis of the aft engine greater than zero to, e.g., allow for a maximum amount of airflow into the aft engine.

Abstract: An aircraft includes a boundary layer ingestion fan defining a centerline and including a plurality of fan blades rotatable about the centerline. The aircraft also includes a fuselage extending between a forward end and an aft end along a longitudinal direction, the boundary layer ingestion fan positioned within the fuselage at the aft end of the fuselage, the fuselage defining an inlet upstream of the boundary layer ingestion fan extending at least about 180 degrees around the centerline of the boundary layer ingestion fan, the fuselage further defining an exhaust downstream of the boundary layer ingestion fan.

Abstract: An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The fuselage defines a profile proximate the boundary layer ingestion fan that is optimized for ingesting a maximum amount of boundary layer air and improving propulsive efficiency of the aircraft. More specifically, the fuselage defines a cross sectional profile upstream of the boundary layer ingestion fan that has more cross sectional area in a top half relative to a bottom half as defined relative to a centerline of the boundary layer ingestion fan.

Abstract: An aircraft is provided including a fuselage and an aft engine. The fuselage defines a top side, a bottom side, and a frustum located proximate an aft end of the aircraft. The frustum defines a top reference line extending along the frustum at a top side of the fuselage, and a bottom reference line extending along the frustum at a bottom side of the fuselage. The top and bottom reference lines meet at a reference point aft of the frustum. The fuselage further defines a recessed portion located aft of the frustum and indented inwardly from the bottom reference line. The aft engine includes a nacelle extending adjacent to the recessed portion of the fuselage such that the aft engine may be included with the aircraft without interfering with, e.g., a takeoff angle of the aircraft.

Abstract: The present disclosure is directed to an aerodynamic inlet guide vane assembly for reducing airflow swirl distortion entering an aft fan mounted to a fuselage of an aircraft. Further, the inlet guide vane assembly is configured for mounting to fan shaft and a nacelle of the aft fan. The inlet guide vane assembly includes a plurality of inlet guide vanes grouped into a plurality of inlet guide vane groups. Each of the inlet guide vanes has a shape and an orientation corresponding to airflow conditions entering the fan. Further, the inlet guide vane groups are spaced circumferentially around the central axis as a function of the airflow conditions entering the fan.

Abstract: An aircraft is provided including a fuselage extending between a forward end and an aft end. An aft engine is mounted to the aft end of the fuselage and defines a centerline. The aft engine further includes a nacelle having a forward transition duct at the forward end of the nacelle. The forward transition duct also defines a centerline and the centerline of the forward transition duct is angled downward relative to the centerline of the aft engine.

Abstract: An aircraft propulsion system includes a boundary layer ingestion (BLI) fan system disposed at an aft end of an aircraft. The BLI fan system includes a fan that is configured to rotate about an axial centerline of the BLI fan system in a first direction of rotation. The BLI fan system includes blades that are positioned at a first pitch angle configured to rotate with the fan. An electric motor operably coupled with the BLI fan system is configured to change a direction of rotation of the fan to a different, second direction of rotation. An actuator operably coupled with the BLI fan system is configured to change a position of the blades of the fan to be positioned at a different, second pitch angle.